Mine roof support for progressive exploitation



0, 1968 K. SPIES ETAL 3,397,543

MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4Sheets-Sheet 1 KLAUS SP\ES WALTER WE\RICH MINE ROOF SUPPORT FORPROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4 Sheets-Sheet 2 Wyn/masKLAUS SPIES WALTER WEIRICH Aug. 20, 1968 K. SPlES ETAL 3,397,543

MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4Sheets-Sheet 5 KLAUS SPIES WALTER WEIRICH ATTORNEY Aug. 20, 1968 K.SPIES ETAL MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17,1965 4 SheetsSheet 4 MUG M ra/r095 KLAUS SPiES WALTER WEIRICH UnitedStates Patent 3,397,543 MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATIONKlaus Spies, Dortmund-Wellinghofen, and Walter Weirich, Dortmund,Germany, assignors, by mesne assignments, to Gewerkschaft EisenhutteWestfalia, Altlunen, Germany, a corporation of Germany Filed Aug. 17,1965, Ser. No. 480,400 Claims priority, applicatigi; Ggelrmany, Aug. 20,1964,

5 9 9 Claims. (Cl. 61-45) ABSTRACT OF THE DISCLOSURE The inventionrelates to support means for progressive mine exploitation and includesa plurality of upstanding spaced mineroof supporting units associated bylongitudinally extending power-operated means positioned between each ofthe units. The sub-assembly of the units include ground-engaging glideplate support members as well as parallel upstanding spaced prop meansextending above the glide plates and cover means on each of the propmeans, The prop means also include power means for raising and loweringthe props relative to the groundengaging glide members and spring meansare arranged to interconnect the upstanding prop means and thegroundengaging means adjacent to the glide plate support means with afeeler member being carried by the cover member of the intermediate propto control the advance of the assembly and the mine exploitation.

This invention relates to a mine roof support for use in progressivemine exploitation wherein the support comprises parallel spacedlyarranged pit props interconnected by means of guiding and advancingmechanisms.

Presently known hydraulic mine roof supports usually comprise two pitprops which are interconnected by means of an advancing mechanism. Theadvancing mechanism comprises, in case of pit props with paralleladvancement means the advancing cylinder proper and parallel guidemeans, and in case of a mine roof support of the type of swingingadvancement it comprises mostly rigid steering means and an advancingcylinder which is arranged either diagonally in the mine roof support oris disposed between the steering mechanism adjacent the mine face andthe conveyor mechanism.

Further, there are also known mine roof supports of the paralleladvancing type which comprise three props which are tied one to anotherby means of an advancing cylinder having two piston rods as Well as bymeans of tie beam like connecting pieces. Furthermore, mine roofsupports which also permit of a swinging type of advancement have beenproposed wherein the leading mine roof support which comprises two propsfollows along in small swinging steps relative to the mine face whilethe principal mine roof support means also follows in swinging steps,but is spaced apart by longer distances.

Moreover, it is also known to secure together central props in units ofthree wherein the two external props are interconnected by means of ayoke on which rests an advancing cylinder for eifectuating theadvancement of the middle prop.

Finally, there is also known a walking mine roof support wherein a groupof three props are interconnected by means of a common advancingcylinder wherein the flanking or outside props are interconnected bymeans of a transversal rod and wherein the props move in a trailingrhythm.

The mine roof support including the above-mentioned 3,397,543 PatentedAug. 20, 1968 particular arrangement of the parallel advancement typehas several disadvantages when used in sloping walls and thick strata.

It has also been found that the summation of the tolerances in theguidance and advancing mechanism as well as the front weight of the mineroof support, particularly that at the top caused by the projecting capmembers, makes the mine roof support wander downhill in sloping stratawhere progressive exploitation is carried out. Since Wandering is notalways equal for each of the supports, the occurrence of unsupportedroof portions as well as mutual entanglement between the respectivesupports is consequently unavoidable. In practice,'it has been attemptedto remedy this situation by untensioning the means controlling the threeprops of the support and thereafter readjusting the support by thealternative use of the advancing cylinder so as to bring the supportinto an increased advancing direction. This procedure, however, has thedisadvantage that although the time of the advancing increases, theefiiciency of exploitation decreases. Furthermore, by untensioning thethree props relative to the support, the condition of the mine roof maysubstantially deteriorate.

When sloping walls or thick strata are encountered relative to thecenter of gravity of the mine roof support particularly where only twoprops are utilized and these lie outside the sole plate, then it ispossible that in case of unintentional untensioning of all four props ofthe support there is a danger of tipping as well as sliding which mayseriously endanger the safety of the mining crew.

Although mine roof supports of the swinging advancement type (includingthe particular arrangements mentioned hereinabove) avoid thedisadvantage of the absence of readjustment possibility in the event ofwandering of the support, they nevertheless have another seriousdisadvantage in that their advancement follows in circular arcs wherebythe advancement of the support means is made quite difficult or evenimpossible if during exploitation the heap to be exploited extends intothe working area.

The above listed embodiments wherein three props are interconnected bymeans of a single advancing cylinder have also another disadvantage inthat (at all times).

when the middle prop is advanced first, the two flanking props followtogether simultaneously or vice versa..

Thus, under these circumstances the advancement is carried outnecessarily in a rigid succession. Accordinglyit is not possible toprovide another order of succession where this arrangement is used foran advancement at will of one of the outside props or the influencing ofthe supports to avoid downward wandering.

By means of the proposed solution thecombined areaadvancement of themiddle prop the advancing cylinders of the two guiding mechanisms may beunequally opperated so that a steering of the entire mine roof supportbecomes possible.

The possibility of an independent advancement of eachindividual prop inthe mine roof support further makes it possible to use one prop as aleading prop and in case of difficult conditions of exploitation followthe mining apparatus with this one particular prop in relatively smallsteps. In this improvement in the art, the leading prop has incorporatedtherein suitable means which provides a supporting force smaller thanthat of the two other props of the mine roof support. With thisarrangement, it is possible that even in case of advancement beingaccomplished in small steps, the undesirable disturbance during theexploitation of the material may be held within tolerable limits.

In accordance with the invention, in order not to increase unnecessarilythe crew for advancing the leading mine roof prop, there is provided aleading prop which, while maintaining a residual supporting force,continuously and automatically or intermittently automatically followsthe mine face in individual steps upon actuation of a contact mechanismthat interconnects the mine face with the leading mine roof prop. Incase the stroke of the advancing cylinder between the leading prop andthe other two principal props of the triple support is eX- hausted, theadvancement of the principal support may be thereby actuated as well.

Accordingly, iti s the primary object of the invention to provide a mineroof support of the type which overcomes the disadvantages mentionedhereinabove.

Another object of the invention is to provide a mine roof support whichis characterized by an arrangement of three props and two normallydisposed guide and advancing mechanisms of which one guide mechanism andadvancing mechanism each interconnect the middle prop with one outsideprop.

Still another object of the invention is to provide a mine roof supportwhich is arranged in such a manner that the individual pit props may beadvanced independently of each other and the mine roof support may besteered by the alternate actuation of the advancing cylinders.

A further advantageous object of the invention is to provide a mine roofsupport comprising parts of a support system having two props, which isso arranged that it may be assembled merely by adding an additional newmember namely, the middle dual stop shaft, to the conventional supporthaving two props.

In materializing the inventive thought disclosed herein, any mine roofsupports of desired construction may be used. Since the advantages ofthe proposed mine roof supports appear particularly in sloping strata,therefore, primarily those kinds of mine roof supports are consideredwhich are springingly interconnected with guiding and advancingmechanisms and which provide for a vertical setting of the beams orprops in the mine roof support after exploitation.

These and other objects and advantages will become apparent from thefollowing description taken in conjunction with the accompanyingdrawings and which;

FIG. 1 is a front elevational view of three interconnected mine roofsupports;

FIG. 2 is a side elevational view of one of the units shown in FIG. 1;

FIG. 3 is a top plan view of the unitary assembly shown in FIG. 1 withseveral of the caps removed for clarity;

FIG. 4 is a side elevational view of the cap of the leading prop insection showing a built-in contact mechanism with one part contactingmine wall face and FIG. 5 shows the same mechanism as FIG. 4, but in anextended position as the assembly advances.

Turning now to the drawings and more particularly that in FIG. 1, themine roof support comprises three conventional prop units 10, 11 and 12arranged side by side with each of them being interconnected by means ofguiding and advancing mechanisms 13 and 13'. The individual prop units10, 11 and 12 extend normal to a sole or glide plates 14, 15 and 16 andare provided at their upper extremity with telescopable hydraulic posts17, 18 and 19. The posts are secured to the sole plates in a knownmanner by means of ball joints and are interjoined elastically by meansof spring elements comprising leaf spring bundles 20 and 21 (FIG. 2).Each prop unit engages the mine roof (not shown) through thelongitudinally extending cap cover members 22, 23 and 24.

The individual prop units 10, 11 and 12 are interdigitated by means ofsingle or double armed stub members 25 and 26 with the guiding andadvancing mechanisms 13 and 13.

In the patent application of Weirich et al., Ser. No. 429,779, filedFeb. 2, 1965, which is also assigned to the assignee of this invention,there is disclosed in greater detail how the ofistanding double armedstub members carried by the guiding and advancing mechanisms areassociated with each of the props shown therein. Thus, it appears tosuffice to point out herein only that the U- shaped brackets carried bythe guiding and advancing mechanisms hereof are removably secured to theprops by the pivotal operator means 27 which carries a shaft (notshown).

The guiding'and advancing mechanisms 13 and 13 are built in such amanner that they are attachable to the support means or adapted tooperate the same even when turned Thus, it is apparent that it ispossible to advance at will first either the left or the right pit prop,i.e., 10 or 12 while it is connected to a respective guiding mechanism13 or 13.

Moreover, by means of a corresponding arrangement of the guiding andadvancing mechanisms and through the required actuation of the doubleaction hydraulic cylinders of the advancing mechanism, the individualprop units may be advanced in any desired order of succession. Further,each pit prop unit may be used at the desire of the workman as a leadingunit. The steerability of the mine roof support is achieved by thealternate actuation of the two cylinders of the advancing mechanism. Indetail the steering is carried out in the following manher:

The inequality in the elevation of the apparatus which is brought aboutby the lowering of the previously advanced middle prop is first taken upby the spring elements 20 and 21, and after the settling of the middleprop 11 and the forward motion process of the two flanking props, thespring elements 20 and 21 move back into their normal position so thatthe two flanking prop units may also swing in the direction of themiddle pit prop unit. This guiding motion may be carried out during theadvancement process without additional manipulation. The same effect canalso be achieved if the two flanking pit prop units are advanced first.

In the event one of the pit prop units of the triple support means isused as a leading prop unit, there are two possibilities for advancingthis leading prop unit. First, that particular unit may be made tocontinuously follow the mine face during which time the cylinders, whichare positioned outboard thereof and intermediate the adjacent prop unitsof the triple support means, are constantly provided with pressure andthe leading prop unit is advanced while the pressure necessary tosupport the cap cover 24 is decreased sufliciently to permit the same toslide along the roof of the mine.

In the embodiment of the invention illustrated in FIGS. 4 and 5 there isshown a portion of the leading prop and longitudinal cap means beneathwhich is arranged a cylinder 35 and within which is slidably arranged arod 36. The rod 36 includes an abutment 37 at its rearward portion whichprovides a sliding support for a spring 38 positioned in the chamberformed by the rear wall of the cylinder and the abutment 37 and at itsfront end includes a feeler member 39 adapted to engage the mine wall40.

The abutment 37 includes a depending nose element 41 which is arrangedto project through an elongated slot provided in the bottom of thecylinder and together with the feeler performs a function which will bebest understood from perusing the description of operation.

Operation The feeler 39 is constantly urged against the mine face bymeans of the spring 38 disposed in the chamber of the slotted tube 35.This condition takes place particularly when the prop is in its settledposition, i.e., not in complete weight-bearing contact with the roof ofthe mine wall. Y

As viewed in FIG. 4, for example, the feeler mechanism carried by theleading prop is in engagement with the mine wall 40. Accordingly,considering FIG. 4 further, when coal is exploited, the mine face isdisplaced towards the right in the view in the drawing and during thistime lever 42 is displaced into a substantially vertical neutralposition. It will be apparent that under the influence of spring 38 thefeeler 39 will maintain its contact with the mine face. In the event asufficiently wide coal strip is exploited (see FIG. 5), the nose portion41 of the abutment 37 causes the lever 42 to move toward the right asviewed in this figure whereupon it will engage contact 43. As soon asthe circuit is closed, a signal is transmitted from a suitable powersupply source (not shown) to the intermediately disposed or leading propunit. As a consequence of this signal the telescopable hydraulicallyactuated spaced posts 1818 are untensioned so that they are freed oftheir contact with the roof. As soon as this happens and throughtransmission of another signal, reciprocable pistons (not shown), whichare positioned within the guiding and advancing mechanisms 13 and 13',are actuated causing advancement of the leading prop toward the minewall. When this prop has attained a predetermined position adjacent tothe wall and the opposite face of the pistons are brought into contactwith the other end of the cylinder cover, another switch is actuatedthus causing the telescopable hydraulically actuated spaced posts 18-18to be raised again into supporting contact with the mine roof orceiling.

It is also possible to work with a residual force of the spacedtelescopable members applied against the roof. Accordingly, the pressurein the telescopable members may be reduced only to such a value thatthey may remain pushed against the ceiling, but only with such a limitedamount of force that can be overcome by the advancing cylinders duringthe sliding movement of the spaced prop units.

In view of the foregoing, it will be apparent that through advancementof the intermediate prop, the feeler 39 is once again pushed backcountering the force of spring 38 and at the same time the rod 32, whichcarries the feeler 39, displaces the switch lever 41 from its neutralvertically extending position into the other contact-making position at44, thus efiectuating advancing movement through the current source ofthe two outboard prop units. These control slides or pushers arrive in aposition in which the associated hydraulically actuated telescopablemembers of the prop units are untensioned so that they will freethemselves from the ceiling of the mine. The decreasing pressure thusafiects the control slide for the guiding and advancing mechanisms 13and 13 in that the opposite sides of the pistons referred to areactivated, whereupon the cylinders are moved forward to advance theoutboard prop units. When this motion is accomplished, a terminal switchprovided within the cylinders of the guiding and advancing mechanisms 13and 13' causes the caps of the hydraulically telescopable posts 17 and19 to be set once again into contact against the ceiling thusterminating a working cycle.

Although only one embodiment of the invention has been depicted anddescribed, it will be apparent that this embodiment is illustrative innature and that a number of modifications in the apparatus andvariations in its end use may be effected without departing from thespirit or scope of the invention as defined in the appended claims.

That which is claimed is:

1. A plurality of upstanding spaced mine roof supporting unitsinterconnected by first power-operated means positioned therebetween andnormal relative thereto comprising, a unitary structure includingground-engaging glide plate support means, parallel upstanding spacedprop means extending above said last named means, cover means on saidprop means, said prop means including second power means for raising andlowering the prop means relative to said ground-engaging means andspring means interconnecting said upstanding prop means and saidground-engaging meansadjacent said glide plate support means, said firstpower means being adapted to advance one of said units relative to itsassociated companion units and thereafter any one of the other of theplurality of said units in sequence.

2. A plurality of at least three interconnected upstanding spaced mineroof supporting units associated by first power-operated meanspositioned between each of said units and normal relative theretocomprising, a unitary structure including ground-engaging glide platesupport means, parallel upstanding spaced prop means extending abovesaid last named means, cover means on said prop means, said prop meansincluding second power means for raising and lowering the prop meansrelative to said ground-engaging means and spring means interconnectingsaid upstanding prop means and said ground-engaging means adjacent saidglide plate support means.

3. A plurality of at least three interconnected upstanding spaced mineroof supporting units as claimed in claim 2, wherein the cover means ofthe intermediately disposed of said units includes control means adaptedto engage the face of a mine wall.

4. A plurality of at least three upstanding spaced mine roof supportingunits interdigitated by first power operated means positionedtherebetween and normal relative thereto comprising, a unitary structureincluding ground-engaging glide plate support means, parallel upstandingspaced prop means extending above said last named means, cover means onsaid prop means, said prop means including second power means forraising and lowering the prop means relative to said ground-engagingmeans and spring means interconnecting said upstanding prop means andsaid ground-engaging means adjacent said glide plate support means,longitudinally extending means interconnecting the cover means of saidspaced prop means and feeler means carried by at least one of said covermeans for controlling the forward motion process of said units.

5. A plurality of at least three upstanding spaced mine roof supportingunits as claimed in claim 4, wherein the feeler means includes anelectro-hydraulic switch means and plural reciprocable means fortripping the same into on and off positions.

6. A plurality of at least three upstanding spaced mine roof supportingunits as claimed in claim 5, wherein the electro-hydraulic meansincludes means adapted to introduce power from said means into either ofsaid first power means and plural reciprocable means for tripping saidswitch means into on and off positions whereby any one of said units maybe advanced relative to its companion interconnected units.

7. A plurality of at least three upstanding spaced mine roof supportingunits as claimed in claim 6, wherein the electro-hydraulic meansincludes a cylindrical element positioned beneath the cover means, saidcylindrical element being provided with an elongated slot means adaptedto confine at least one of said reciprocable means to a predeterminedpath of travel.

8. A plurality of at least three upstanding spaced mine roof supportingunits as claimed in claim 7, wherein the cylindrical element includes anextensible spring means adapted to urge the plural reciprocable meanslongitudinally relative to said cap means.

9. A plurality of at least three upstanding spaced mine roof supportingunits as claimed in claim 4, wherein the feeler means is associated withthe cover means of the intermediately disposed prop means.

(References on following page) 8 References Cited FOREIGN PATENTS UNITEDSTATES PATENTS 1,190,532 4/1959 France.

947,078 1/ 1964 Great Britain. 2,859,022 11/1958 Frye 6145.2 3,246,7304/1966 Bolton et a1. 61-45.2 5 DAVID WILLIAMOWSKY, Primary in r-3,309,880 3/1967 Potts et a1. 61-45 D. L. TAYLOR, Assistant Examiner.

